These fragments I have shored against my ruin.

A Few No-Fee Manhattan Landlords Online

Here's a short and obviously incomplete list of companies I was able to find that own multiple buildings in Manhattan and post their vacancies online. Even though I ended up getting my apartment through a broker, I found this kind of useful. To compile this list, basically I went to Craigslist and searched for apartments for sale by owner, then checked out the website of the owners. You can probably find more that way. Also I searched on Googe for "landlords" and one or two of the company names below, and I would often find a list of landlords including other names on the list - you could try that too. The other thing I did was call my friends' landlords to ask about vacancies directly.

No Fee Rentals, aka Jakobson Properties - we know this site because someone we know got an apartment in one of these buildings through a broker. They have tons of very affordable but cramped downtown apartments

Sirkin Realty - very nice people with affordable but low-rent properties. I ran into other Craigslist people while scoping out these places, but never saw anyone actually sign a lease.